But when it comes to seeking the death penalty in specific cases, both sides – for and against — agree that government officials need to play by the rules.

A state Court of Appeals ruling Thursday affirmed a lower court decision that prosecutors sidestepped the rules in the case against David Bueno. While trying to persuade a jury to convict and ultimately have Bueno executed for a 2004 prison murder, prosecutors for the 18th Judicial District withheld bombshell evidence that pointed to his innocence.

Prosecutors are legally and ethically obliged to disclose all evidence, regardless of whether it helps or hurts their cases. “As the trial court noted, ‘[i]t is apparent .. . that a conscious decision was made at some point early in this case to keep the information from the [d]efendant….ʼ,” the appeals court ruled.

Former District Attorney Carol Chambers shrugged off Lincoln County District Court Judge P. Douglas Tallman’s finding of prosecutorial misconduct by appealing his ruling to overturn Bueno’s conviction. Her successor, George Brauchler, seems equally unbothered by his office’s failure to have disclosed key facts to Bueno’s defense lawyers.

“We respectfully disagree with the Court of Appeals’ decision and are assessing whether to further appeal,” said Lisa Pinto, a spokesman for Brauchler, who has said he may challenge John Hickenlooper for governor next year.

Misconduct in Bueno’s prosecution exposes uncomfortable truths about the win-at-all-costs ethos among lawyers in high-profile death penalty cases.

“We’d like to think that when the stakes are the highest, everybody’s on their best behavior. But what happened here was a hijacking of the truth,” said Bueno’s trial lawyer, Derek Samuelson.

“People are kidding themselves if they believe this doesn’t happen west of the Mississippi. They’re kidding themselves if they think an innocent person in Colorado couldn’t wrongfully end up on death row and fall prey to the executioner.”

Death penalty abolitionists say the appellate ruling marks another in a string of reasons to end capital punishment.

“When people’s lives are on the lines, there’s no room for mistakes. But the death penalty is a system that makes mistakes, and the Bueno case clearly shows that,” said Lisa Cisneros, executive director of Coloradans for Alternatives to the Death Penalty.

Thursday’s misconduct ruling stems from the 2004 stabbing death of Jeffrey Heird in Limon Correctional Facility – a prison whose long history of violence has earned it the reputation as the “thunderdome” of Colorado’s system. Heird, deemed to be a white supremacist by the corrections department, had been labeled as a rat for not warning white supremacists about a drug bust in the prison.

Immediately after his murder, prison officials found two notes. One stated, “Killers are Bueno and Perez.” Alejandro Perez, a fellow inmate, later faced the same murder charges as Bueno.

The other note, allegedly written by the Aryan Nation, threatened to “exterminate” white inmates who “refuse to accept their proud race.” The note included a hit list of certain white supremacists as specific targets. Among them was David Hollenbeck, who suffered blunt chest trauma three days after Heird’s murder and later died in a Denver hospital. “Hollenbeck need (sic) to be taught a lesson,” the second note stated.

Prosecutors turned over the first note to Bueno’s defense team, but removed the second from the evidence file. Hollenbeck’s death after an apparent attack the same week as Heird’s murder also wasn’t disclosed.

Prosecutors were fully aware that the Aryan Nation letter and facts surrounding Hollenbeck’s death would have helped Bueno’s defense, which centered on the theory that white supremacists at Limon murdered Heird and blamed his killing on Bueno and Perez.

A jury took nearly four days to find Bueno guilty of first-degree murder, and about two hours to sentence him to life in prison rather than death by lethal injection, as Chambers had sought.

At the order of the judge in Perez’s case, the second note – allegedly written by the Aryan Nation — was handed to defense lawyers in 2009, about five years after the prosecution first had it and 15 months after Bueno was convicted. With the benefit of that letter, Perez secured a jury acquittal in three hours.

“The facts of both cases were largely he same. Perez’s acquittal was absolute proof that the evidence would have made a difference” in Bueno’s trial,” Samuelson said.

Bueno’s trial judge was outraged. In a rare move, Tallman sanctioned prosecutors for their misconduct by overturning Bueno’s conviction and ordering a new, fairer trial. Bueno, 49 and doing time for robbery and burglary, has spent nearly a decade in solitary confinement. His mandatory release date is in 2019.

A second trial for the Heird murder has been on hold as DAs appealed Tallman’s decision by arguing that he was abusing his judicial discretion.

Prosecutors involved in the case against Bueno since have won elected office. Dan May is the District Attorney in El Paso County and Robert Watson went on to become DA for the 13th Judicial District.

Another of the prosecutors, Rich Orman, is leading Brauchler’s charge to execute James Holmes in connection with the Aurora theater shooting.

During Bueno’s trial, Orman openly mocked as speculation the defense theory that Heird died at the hands of his fellow white supremacists.

“Now that two courts have confirmed that the prosecutors from the 18th Judicial District withheld critical evidence when a man’s life was on the line, one can’t help but question what’s going in other cases where some of the very same people are seeking the death penalty,” Samuelson said.

Several groups, including the American Civil Liberties Union of Colorado and the NAACP, have taken issue with how the death penalty is sought in the state. They cite a study last year showing strong biases against ethnic minorities. In a state with a black population at 4.3 percent, all three men currently on death row – Nathan Dunlap, Robert Ray and Sir Mario Owens — are black. Their cases, also prosecuted in the 18th judicial district, have come under scrutiny because of allegations of prosecutorial misconduct, including witness tampering. A judge has sealed records of their court proceedings.

“If there was misconduct in Bueno’s prosecution, how do we know there wasn’t misconduct in those cases, especially if the records are sealed?” Cisneros said.

Activists and government watchdogs are calling on Hickenlooper — who last session quashed an effort to repeal the death penalty — to make good on his promise to have what he called a “statewide conversation” on capital punishment.

Said Cisneros: “There has been no such conversation, nothing but silence, probably because talking about the death penalty wouldn’t help Hickenlooper win re-election next year.”

*Correction: The original version of this story reported that there are two men on death row in Colorado. There are three. In May 2013, Gov. Hickenlooper granted Nathan Dunlap a temporary reprieve. Dunlap was scheduled to be executed later that summer. His sentence hasn’t changed.